I hate to rain on everyone's parade of self righteousness, but I fail to see how listening to headphones is different from just cranking your car's stereo. Hearing is almost completely inconsequential to driving. When was the last time you heard someone signal anything useful with their horn? Emergency vehicles have flashing lights which are much more noticeable than sirens. Many modern luxury cars also isolate you to a remarkable degree and AFAIK safety nazis don't have their panties in a bunch about them. Finally, deaf people drive all the time without incident.

If you get into accident while wearing headphones it will be because you were paying too much attention to the music instead of the road, not because of the way you were listening to the music. If you're going to condemn using headphones while driving you'll need to condemn car stereos too. And traveling with passengers, and cup holders, and drive-thrus, and roadside billboards, and lots of other things that are more distracting. That's at least a logically consistent stance, if not a popular one. I'm willing to take this back I someone has a few studies to back them up, or at least propose some mechanism of action I didn't already eviscerate.

That's why I only use my car stereo when I have the windows open. Even music at a moderate volume is enough to block out the sound of an approaching emergency vehicle.

The only time I use headphones in the car is when I either A) Know exactly where I'm going so I don't have to pay attention to my route. I can fully concentrate on the traffic. B) On highways outside of towns, where the only threat is either in front or behind which is immediately noticeable by watching your mirrors as you should (same with emergency vehicles, flashing lights in the rear view mirror is hard to miss). When I arrive in the town I'm driving to and I don't know my way well, I immediately remove the headphones and make sure the car stereo system is silent also.

And if you had a Lexus you'd have to drive with your widows down all the time too.

Good thing I live in California where the weather is usually nice enough to do that And there's no way I can afford a Lexus until I at least graduate from college. For now, my 1998 Subaru Outback is just fine.

I'd bet that would put you in the minority of people who buy those. Near as I can tell people buy Lexuses (Lexi?) and other super isolating luxury cars do so because they're quiet. My point here is that people need to have a consistent position. If you think isolation caused by headphones is dangerous and they should be banned while driving then you also need to be in favor of banning car stereos and super quiet luxury cars. If you think its dangerous because its a distraction and should be banned for that reason then you need to be in favor of banning other distractions like stereos and talking to passengers.

If you held those positions I would still disagree with you (because I think hearing is almost irrelevant to driving) but I would respect your position because it is self-consistent.

I really think the problem with earphones is that IEMs and headphones, especially good ones, tend to pull you into another world -- a lethal distraction when you are driving. It isn't the isolation that is the problem at all.

Does that mean do I think stereo is a problem as well? Yes, I do, especially if they are so loud that you start head-banging to your music. However, if the stereo is down low, then it is nothing more of a background noise. As long as your attention is on the road, not on the music, you are fine.

I actually did a "road test" to see how it affected my driving. I used an open ear design and went from Rockport Texas to Austin, Texas about a 4 hr drive. I took them off in Austin traffic and often don't even have the radio on - I just don't like traffic.

I found the headphones to be no distraction and I could still hear all the cars going by. I found I didn't need to change channels as radio listeners might nor find CDs to put in the player. The music was relaxing and kept me awake as well.

I have modified my position and see no problem with wearing OPEN EAR (Circumaural) headphones while driving in anything but heavy traffic.